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SECTION 4.4 SITE INVESTIGATION ACTIVITIES remains stationary in the well, groundwater will continue to fill the vials and then cascade from the vials into the KabisTM sampler reservoir The vials and reservoir fills in approximately 10 minutes The discrete groundwater samples were analyzed at the Shop 10 site using a mobile laboratory operated by Environmental Laboratories (ONSITE) for the following analyses e TPH-g in accordance with EPA Method 8015 modified • BTEX and MTBE in accordance with EPA Method 8260B Nitrogen as nitrate and sulfate analyses in accordance with EPA Method 300 0 were conducted by a subcontractor to ONSITE (Curtis and Tompkins) During collection of the discrete samples, URSGWC monitored for the following groundwater quality parameters pH, conductivity, temperature, dissolved oxygen, and turbidity The field monitoring data are presented in Table 5-1, and are recorded on well sampling logs included in Appendix A Quarterly groundwater monitoring at Shop 10 was conducted between March 29 and April 2, 1999 by PSI under contract to Caltrans The routine periodic groundwater monitoring at the site included measuring depth to groundwater in the 12 onsite groundwater monitoring wells, and two vapor monitoring wells, purging of each well, and collecting groundwater samples for analytical testing The depth-to-groundwater measurements were used by PSI to evaluate groundwater surface elevations and horizontal gradients Depth to groundwater measurements and analytical data for the April 1999 monitoring event are included in Table 3-2 The results for the quarterly event are discussed along with the discrete vertical sampling in Section 5 0 1 4.3 SLUG TEST PROCEDURES ' SingIe-well hydraulic tests (slug tests) were conducted at three wells, identified as MW-11, MW-13, and MW-24, at the Shop 10 site Slug tests consisted of lowering a mandrel into each of the three wells to cause an instantaneous rise in water level The fall in water level to static water level conditions was measured using a water level meter to the nearest 0 01 foot Once static water level conditions existed, the mandrel was removed from the water column to cause an ' instantaneous fall in water The subsequent recovery of the water level to static conditions was measured with a water level meter The data were down loaded in the AgtesolvTM groundwater modeling program to the estimate hydraulic conductivity for each slug test The data were analyzed using the Bouer and Rice Method for confined aquifers and Cooper-Bredehoeft- Papadopulos Method for unconfined aquifers Slug test procedures are presented in Appendix C 1 S IPRO.MloaoiooUMHOPIMSHOPIOSILOOC 4-3 UBS Greiner Woodward Clyde